Thermal IR detectors are heated by the incident IR radiation and provide detection through the change in a measurable parameter. They are used in contact-less temperature measurement, night vision cameras for defense, security and surveillance applications, search and rescue and many other thermal imaging applications. For these types of detectors, wavelengths of interest are mainly in the atmospheric windows—ranging from 3 to 5 (MWIR) and 8 to 14 (LWIR) μm wavelength ranges, due to the high transmission through atmospheric air of more than 80% and peak IR emission of room temperature bodies is at 9-10 μm of wavelengths. Until recently, the important market of thermal imaging was mostly made of semiconductor-based, cooled quantum devices which measure photon intensity by electron-hole pair generation. The sensitivity and abilities of these quantum detectors far surpassed thermal detectors, leaving them only useful for a small group of low-cost, low performance products. To achieve better results of thermal detectors, the thermal properties of the device needed to be enhanced.
Current microbolometer technology uses serpentine structured electrode arms (See FIG. 1, prior art) suspended on top of the substrate by using surface micromachining technique. The minimum reported thermal conductance using this method is 1×10−7 W/K. Since the performance of the microbolometer and its figures of merits such as responsivity, detectivity and noise equivalent temperature difference (NETD) depend on the value of thermal conductance; reduction of thermal conductance will improve the figures of merits. By using an improved and new design, this invention reports the improved figures of merits and better performance of a microbolometer. With the advent of new nano and micro fabrication techniques such as nano-imprinting or electron beam lithography, structures less than or around 100 nm feature size can be patterned. To take advantage of this technology, the current invention includes the use a design which includes nano-meter size studs to reduce the thermal conductance at least an order of magnitude than the current state-of-the-art.